Tensioning device for seat belt

Abstract

A tensioning device for a seat belt for protecting a passenger at an urgent time by restraining him on his seat by a tensioned seat belt. A base is adapted to be fixed to a vehicle, and spaced from the base is a plate to which is connected one end of a seat belt which itself is movably inserted through the central portion of the base. At least one flexible cylindrical body is connected between the base and the plate to form a sealed chamber. The cylindrical body is normally in a contracted state, and a gas supplying means which supplies a high pressure gas at an urgent time into the sealed chamber elongates the contracted cylindrical body into a flat sheet to tension the seat belt and restrain the passenger on his seat.

Dependencies are inferred from the claim text.